ML19208D435

Forwards Comparison of Util Mod Proposals & NRC Positions Re Grid Undervoltage Protection,Per NRC 790811 Request for Design Mods & Changes in Tech Specs.Tech Spec Changes Being Developed & Will Be Submitted After Required Review

ML19208D435
Person / Time
Site:	Oyster Creek
Issue date:	09/25/1979
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Office of Nuclear Reactor Regulation
References
TASK-08-01.A, TASK-RR NUDOCS 7909280422
Download: ML19208D435 (4)

Text

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Jersey Central Power & Light Company

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Morristown, New Jersey 07960 (201)455-8200 September 25,1979 Director Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Subject:

Oyster Creek Nuclear Ge.eratire Station Docket No. 50-219 Grid Undervoltage Protection By letter dated August 11, 1979, it was requested that JCP&L propose design modifications and changes in the Technical Specifications based on the guidance contained in the NRC staff positions enclosed in your letter of June 3, 1977.

We have reviewed the staff positions and developed a design modification to install the second level undervoltage protection system in order to mitigate the consequences of a sustained degraded grid voltage condition. Enclosure 1 presents a cmparison of our modification proposal and the staff positions. The proposed secorJ level undervoltage protection system is currently scheduled for installation during the upcming refueling outage in January,1980. Technical Specification changes for this system are currently being developed and will be submitted after the required review pursuant to Section 6 of our Technical Specifications.

Very truly yours, f&

Ivan R. Finfro

, Jr Vice President 7009280 VAR 1033  :

Jersey Central Power & Light Company is a Member of the General Pubhc Ut hties System

ENCLOSURE 1 .

DESIGN COMPARISON TO NRC POSITIONS NRC POSITIONS JCP&L PROPOSED ACTIONS

1. Second level of Under or-Over Voltage Protection I. Second level of Under-or-0ver Voltage Protection with a Time Delay. with a Time Delay.

a) The selection of voltage and time set points a) An analysis of the voltage requirements of the shall be determined from an analysis of the safety related loads at all onsite distribution voltage requirements of the safety-related levels was performed by Durns and Roe, Inc. As a loads at all onsite system distribution levels. result of this analysis, JCPCL will implement a voltage set point of 3666 volts with a time delay of 10 seconds.

b) The voltage protection shall include coinci- b) JCP&L will implement a 2 out of 3 coincidence logic dence logic to preclude spurious trips of for tripping.

the offsite power source.

c) The time delay selected shall be based on the c) The time delay selected is based on the following conditions: following conditions:

1) The allowable tin e delay, including margin 1) The time delay selected, including margin shall not exceed the maximum time delay does not exceed the maximum time delay that is assumed in the FSAR accident that is assumed in the FSAR accident analysis.

analysis.

2) The time delay 55all minimize the effect 2) and 3) The time delay was selected such that of short duration disturbances from short duration disturbances do not reduce reducing the availability of the offsite the availability of the offsite power source, power source (s); and and such that subjecting the system to a degraded voltage condition for this allowable

__. 3) The allowable time duration of a degraded time duration does not result in the failure CZ3 voltage condition shall not result in of safety systems or components.

L-; failure of safety systems or components.

Le4 The basis for selecting 10 seconds for the time delay is due to the following:

r-a) The largest motor start duration is 7 second b) During degraded voltage conditions, the cont power fuses in vital motor control centers will maintain their integrity for at 1 cast 18 seconds. .

ENCLOSilRE I (CON'T)

NRC POSITIONS JCPCL PROPOSED ACTIONS

, d) The voltage monitor shall automatically d) The voltage monitors will automatically initiate initiate the disconnection of offsite the disconnection of the of fsite power sources power sources whenever the voltage set whenever the voltage set point and time delay point and time delay limits have been limits have been exceeded.

exceeded.

i c) The voltage monitors shall be designed to c) The system design satisfi'es the requirements of satisfy the requirements of IEEE-Std. IEEE-Std. 279-1971, " Criteria for Protection 279-1971, " Criteria for Protection Systems Systems for Nuclear Power Generating Stations.

for Nuclear Power Generating Stations.

f) The Technical Specifications shall include f) Technical Speci fications are being prepared to limiting conditions for operation, surveil- address the NRC position and will be submitted lance requirements, trip set points with after the required reviews, as.per the Technical minimum and maximum limits, and allowable Specifications, Section 6, are completed.

values for the second-level protection monitors.

2. Interaction of Onsite Power Sources with Load 2. Interaction of Onsite Power Sources with Load Shed Shed Feature. Feature.

a) We require that the current system designs a) The second level of voltage protection will be automatically prevent load shedding of the blocked automatically when the emergency buses emergency buses once the onsite sources are are being fed from the onsite source. The new supplying power to all sequenced loads on voltage protection system will be reinstated the emergency buses. The design shall also automatically when the onsite source supply include the capability of the load shedding breakers _.'c tripped.

feature to be automatically reinstated if.

the onsite source supply breakers are

--. tripped. The automatic bypass and rein-c3 statement feature shall be verified during L-J the periodic testing identified in Position (sa 3, I

L ENCLOSURE 1 (CON'T) ,

NRC POSITIONS JCP&L PROPOSED ACTIONS 3 Onsite Power Source Testing. 3 Onsite Power Source Testing We require that the Technical Specifications Testing procedures are being prepared and will be include a test requirement to demonstrate the implemented upon approval and installation of the full functional operability and independence new voltage protection system. The testing require-of the onsite power sources at least once per ments will be incorporated into the Technical Speci-

18. months during shutdown. The Technical fications which will be submitted at a later time.

Specifications shall include a requirement for tests: 1) simulating loss of offsite power in conjunction with a safety injection actuation signal; and 2) simulating interruption and 4. Voltage Regulators subsequent reconnection of onsite power sources JCP6L plans to install voltage regulators on the to their respective buses. Proper operation Primary side of both Start up Transformers during shall be determined by: its next refueling outage (scheduled for January 1980). These new voltage regulators will enable a) Verifying that on loss of offsite power the distribution system to boost the incoming voltage the emergency buses have been de energized to the Oyster Creek plant by up to a maximum of 10%.

This will result in more acceptabic voltage values and that the loads have been shed from the for the onsite distribution network during degraded emergency buses in accordance with design requirements. grid voltage conditions.

b) Veri fying that on loss of offsite power the diesel generators start from ambient condition on the autostart signal, the emergency buses are energized with perma-nently connected loads, the autoconnected emergency loads are energized through the load sequencer, and the system operates for five minutes while the generators are loaded with the emergency loads.

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(,q c) Verifying that on interruption of the onsite sources the loads are shed from the emergency buses in accordance with design requirements and that subsequent loading of the onsite

[ - sources is through the load sequencer.